withSubstDTDEntities yes/no :
switch on/off entity substitution for general entities defined in DTD validation.
Default is yes.
Switching this option and the validation off can lead to faster parsing, in that case
reading the DTD documents is not longer necessary.
Only used with XML parsed documents, not with HTML parsing.

withSubstHTMLEntities yes/no :
switch on/off entity substitution for general entities defined in HTML validation.
Default is no.
Switching this option on and the validation and substDTDEntities off can lead to faster parsing, in that case
reading the DTD documents is not longer necessary, HTML general entities are still substituted.
Only used with XML parsed documents, not with HTML parsing.

reads Haskell homepage with HTML parser, ignoring any warnings
(at the time of writing, there were some HTML errors),
with http access via libCurl interface
and proxy "www-cache" at port 3128,
parsing is done with tagsoup HTML parser.
This requires packages "hxt-curl" and "hxt-tagsoup" to be installed